I bought about 7-8lbs of garfgrunge it worked fine, but If I were to do it again I would definitely buy from liverocks.com or elsewhere instead. $5 a lb is too much $ for what I got from garf.
The grunge I got didn't have as much "cool stuff" as it was purported to have.
A couple scoops of substrate from the bottom of my LFS
tank on the other hand, had TONS of detrivores, critters, pods
And I would bet a bundle that the live sand from liverocks.com would be freaken' awesome. Liverocks.com is way excellent.
So exactly what RR69 said.. no complaints really but I will go elsewhere in the future. And yes it is exactly that, crushed rock with muck.